MAX1791

High-Efficiency, 10-Pin µMAX, Step-Down Controllers for Notebooks


Please check latest availability status for a specific part variant.

Description

The MAX1762/MAX1791 PWM step-down controllers provide high efficiency, excellent transient response, and high DC output accuracy needed for stepping down, high-voltage batteries to generate low-voltage CPU core, I/O, and chipset RAM supplies in notebook computers and PDAs.

Maxim's proprietary Quick-PWM™ pulse-width modulator is a free-running constant on-time type with input feed-forward. Its high operating frequency (300kHz) allows small external components to be utilized in PC board area-critical applications such as subnotebook computers and smart phones. PWM operation occurs at heavy loads, and automatic switchover to pulse-skipping operation occurs at lighter loads. The external high-side p-channel and low-side n-channel MOSFETs require no bootstrap components. The MAX1762/MAX1791 are simple, easy to compensate, and do not have the noise sensitivity of conventional fixed-frequency current-mode PWMs.

These devices achieve high efficiency at a reduced cost by eliminating the current-sense resistor found in traditional current-mode PWMs. Efficiency is further enhanced by their ability to drive synchronous-rectifier MOSFETs. The MAX1762/MAX1791 come in a 10-pin µMAX® package and offer two fixed voltages (Dual Mode™) for each device, 1.8V/2.5V/adj (MAX1762) and 3.3V/5.0V/adj (MAX1791).
MAX1762, MAX1791: Typical Operating Circuit MAX1762, MAX1791: Typical Operating Circuit Enlarge+

Key Features

  • High Operating Frequency (300kHz)
  • No Current-Sense Resistor
  • Accurate Current Limit
  • ±1% Total DC Error over Line and During Continuous Conduction
  • Dual Mode Fixed Output
    • 1.8V/2.5V/adj (MAX1762)
    • 3.3V/5.0V/adj (MAX1791)
  • 0.5V to 5.5V Output Adjust Range
  • 5V to 20V Input Range
  • Automatic Light-Load Pulse Skipping Operation
  • Free-Running On-Demand PWM
  • Foldback Mode™ UVLO
  • PFET/NFET Synchronous Buck
  • 4.65V at 25mA Linear Regulator Output
  • 5µA Shutdown Supply Current
  • 230µA Quiescent Supply Current
  • 10-Pin µMAX Package

Applications/Uses

  • 2-Way Pagers
  • Analog Cellular Phones
  • Digital Cellular Phones
  • Digital Still Cameras
  • Notebook Computers
Part Number VIN
(V)
VIN
(V)
VOUT1
(V)
VOUT1
(V)
Preset VOUT
(V)
Output Adjust. Method IOUT1
(A)
Switch Type Synchronous Switching DC-DC Outputs Oper. Freq.
(kHz)
Package/Pins Budgetary
Price
min max min max max See Notes
MAX1762  5 20 0.5 5.5
1.8
2.5
Preset
Resistor
2 External Yes 1 300
µMAX/10
$2.18 @1k
MAX1791 
3.3
5
µMAX/10
$3.04 @1k
See All Step-Down Switching Regulators (341)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.


MAX1791EVKIT: Evaluation Kit for the MAX1791, MAX1762

Quality and Environmental Data

Request Reliability Report for: MAX1791 
Lead-Free Package Tin (Sn) Whisker Reports
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >

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